Friday, September 23, 2011

Maya - Unwrapping - Uvs

I use exclusively Maya Unwrapping Tool for Uvs. It can be also used with combinaion of UV Master plugin in Zbrush. I don't rely too much on UV master, but its great for fast and quite accurate uvs in the beggining of the process.

The Maya process is like this:

Select faces of the model (or you can select the whole model itself) - go to (Polygons) Create Uvs, there are a couple of types:
Planar (flat projection)
Cylindrical (for cylindrical objects)
Spherical (I rarely use it)
Automatic (a fast way to have your uvs done, but automatically organized, so not so good for precise texturing).

To check your Uvs go to (Polygons) - Edit UVs - UV Texture Editor.
To be able to work with your Uvs you have to select (right click - choose UV).
To be able to select different Uv parts - right mouse click -> UV, select uv vert in Uv Texture Editor, right mouse click choose To Shell.

1. UV Lattice tool - a lattice for uvs
2. Move (w), Rotate (E) and Scale (R) tools, to mve, rotate and scale the selected uvs.
3. Unfold and Relax Tool - when you have selected uv verts click this tool and slide on option unfold to unforl, or Relax to relax uvs.
4. Uv Smudge tool - smudges or moves SELECTED uv verts
5. Select Shortest Edge path tool
6. Flip Uvs horizontally *
7. Flip Uvs vertically *
* (be careful using the flip tools - it can flip the uvs in the wrong direction, check with your texture pattern if the uvs are flipped the right way - dont use checker box pattern, use a pattern which has letters or numbers as well as checkers).
8. Rotates uv CCW (to the left)
9. Rotates Uv clockwise (to the rigth)
10. Cut Uvs (separate the uvs along the selected edges). The best way to cut uvs is when you have selected EDGES. In order to succesfully cut the uvs and make uv parts - the edges must not have a vertex or face connecting the parts you want to separate, so either use edge loops, or manually select the edges of irregular shapes.
11. Separate the selected UVs into one for each connected edge.
12. Sew the selected edges or uvs together (no movement of the uvs)
13. MOVE and sew the selected edges
14. Select faces to be moved in UV space
15. Snap selected Uvs to user specified grid
16. Unfold selected uvs
17. Automatically move Uvs for better texture space distribution
18. Align the selected verts on the left hand vertical side
19. Align the selected verts on the right hand vertical side
20. Align the selected verts on the horizontal (bottom) side
21. Align the selected verts on the horizontal (top) side

46. Toggle Copy/Paste for faces/uvs
47. Cycles the UVs of the selected face counter clockwise
----------------------------------------------------------------------------------------------------------------
MOST IMPORTANT COMMANDS AND OPTIONS:

Placement Settings:
Region Preset: all options to choose from...
when Numerical Settings is selected you can type numbers in the active fields.

*If in those settings UVLayout is acting weird and does not organize the shells according their size, thats means you have uv's flipped or doublesided uvs. Unfold all the shells then and everithing should seem blue (check button N 31 in the graph above). Then apply UVLaouyt command.

*********************************

UV LAYOUT for precise moving UVs from one Square Map to Another even with flipped Uvs

Layout Uv Shells - Even with UVs that are flipped the settings above will allow you to move the selected Uv shells to the same space but on different square.
Layout Objects - Single or multiple objects (non_overlapping)
Prescale - None
Flip reversed is OFF
Shell layout- None
Scale Mode - Uniform
Shell stacking - Shape
Rotate - None
Placement settings - Region preset - Numerical Entry
Scale U and Scale V stay at 1 alwaysOffset U and Offset V are the numbers you need to change in order to relocate the Uvs to a different quadrant. Values -2, -1, 1, 0, -1, -2, etc
----------------------------------------------------------------------------------------------------------------UV SNAPSHOT:
Have your model selected. All Uvs must be inside the Top Right hand square. Right click choose UV, select all uvs, go to Polygons->> Uv Snapshot (on the bottom). By default Maya saves them in folder "images" as outUv (you may change that folder by clicking Browse).
Choose a size for the texture (keep aspect ratio)
Use Targa, Jpg, Bmp or any other file format).
UV Range Options - Normal (0 to 1) - here you point to Maya which UV square to be snapshoting (default is 0 to 1).
----------------------------------------------------------------------------------------------------------------
Move Vertex along with Uv verts.
In move (and scale tool) Tool Settings CHECK ON "Preserve Uvs". Now when you move your vertex the uv will follow. And the opposite, when you dont want the uv to follow movement or scale on vertexes, uncheck "preserve Uvs".
--------------------------------------------------------------------------------------------------------------
Some tips:
If you have place2dtexture missing - when assigning files to shaders in maya - when you click on color swatch will bring up Create render node option (on the top make sure you have "Witch New Texture Placement" - CHECKED, otherwise it will not create the place2dtexture node!
You can also create it separately and connect it to the file.
----------------------------------------------------------------------------------------------------------------

About Me

I am a 3D Artist in the New York Area for about 7 yrs, concentrating in the Gaming Industry as a Character Artist and Modeler. Before that I have worked for about 10 years in the 2D industry with Photoshop being a Retoucher for various fashion magazines, catalogues and music albums.
Check my Portfolio website to see my ART.